BBCJamil Hassan, one of the most feared men in Bashar al-Assad’s Syrian regime, wanted for the torture and killing of civilians, was shaking as he walked down the stairs of his apartment block.Outside, the 72-year-old climbed into a car in a small convoy with his family and a handful of security guards, just a few suitcases between them.His neighbour and her teenage son watched.”I knew the moment I saw them flee that Assad had fallen,” she says.When we entered Hassan’s apartment a few days later, signs of the family’s hasty departure were everywhere.In the fridge was a half-eaten carrot cake with a knife still on the plate. The beds were strewn with clothes and empty shoeboxes. Flowers wilted in a vase in the dining room, and cups and plates had been left to dry by the sink.A framed photo of a smiling Hassan and Assad hung on the wall of the study, with text reading: “Our skies are for us and forbidden to others”.Hassan, referred to as “the butcher” by many civilians on his street, was one of Assad’s most menacing enforcers. He led the Air Force Intelligence and oversaw a network of detention facilities including the notorious Mezzeh Prison, where detainees were routinely tortured.He is one of many senior regime figures wanted or sanctioned around the world who have abandoned their homes in affluent areas of Damascus and vanished.Finding these men who ruled Syria with an iron fist will be difficult. Some fear they will strike political deals abroad and evade justice.Hayat Tahrir al-Sham (HTS), which led the campaign to topple the regime, has vowed to search for them inside Syria. Rebels aligned with the group now occupy Hassan’s apartment and a handwritten note on the front door warns people not to enter.When we asked them where Hassan might have gone, one grinned and replied: “I don’t know – to Hell.”‘His guards threatened to kill my dog’Many apartment shutters on Hassan’s quiet street in central Damascus are now closed. Knocks on doors go unanswered.Those who will speak tell us about their fear at living on a street with a wanted war criminal. “We were so afraid to talk,” says the woman who watched him flee. “It was terrifying to live next to them.”Hassan is wanted in the US for “engaging in conspiracy to commit cruel and inhuman treatment of civilian detainees, including US citizens”. He was convicted in absentia earlier this year in France for his role in imprisoning, disappearing and torturing two Syrian-French nationals. Germany wants him too. An Interpol Red Notice shows a photograph of Hassan alongside a note that he is wanted for “conspiracy to commit war crimes”.He was placed under travel bans and had his assets frozen over the repression of civilian protesters. In April 2011 the US says Air Force Intelligence personnel fired tear gas and live ammunition at protesting crowds in Damascus and other cities, killing at least 43.People on the street describe a formidable figure who was unapproachable and always surrounded by guards.A makeshift security post outside Hassan’s apartment building was constantly staffed by military personnel. The night before the regime collapsed, the men simply took off their uniforms and discarded their weapons, according to another neighbour.”It was the first time I’d seen this post with no lights, no sounds, no noise,” says 27-year-old Amr al-Bakri, a filmmaker who lives with his family in the building next door.He said locals “knew what he did to the Syrians – outside of Damascus and in Damascus – so we know it but we can’t say anything, just ‘good morning sir’. He’d say nothing back.”Amr says his family had to give away their pet dog after Hassan’s guards threatened to kill it if it didn’t stop barking. When Amr’s family asked for the guard post to be moved from outside their home, they were told they should move house instead, he says.The guards would run regular inspections on the street and check the bags of visitors.”Sometimes if I had a plumber or handyman to come and fix something one of the guards would come and check if there was really something that needed to be fixed,” says the woman living in Hassan’s building.Neighbours also say Hassan had a “golden line” for electricity that meant his family’s lights were always on, while other homes in the neighbourhood were in darkness.The electrician called to fix any problems at the apartment says he knew Hassan over many years “but only from a distance”. “[Hassan] was very strict – a military personality,” the man says. “He was a butcher… He had no mercy.”The man told BBC News he had been in prison – not at Mezzeh but elsewhere – and was tortured there.A local shopkeeper, Mohammed Naoura, says he didn’t like Hassan but that you had to appear to support him.”We are happy now,” he adds. “Nobody believed this would ever happen.”Guns on sofas and underground swimming poolsHussam Luka, head of the General Security Directorate (GSD), was less well-known among residents but had an apartment underneath Hassan.His “ruthless, smooth-talking nature” reportedly earned him the nickname “the spider” – and he’s under sanctions in the EU, US and UK.A UK sanctions list says he was “responsible for the torture of opponents in custody”, while the US Treasury Department says he “reportedly committed a number of massacres” while working in Homs.The White House has said he is one of a small group of officials who might have information about missing American journalist Austin Tice.At his home on Monday, rebels were dismantling furniture to be put into storage. They said they arrived after looters had already taken many of the most expensive items.A photo of Luka and Assad remained, printed in different sizes and styles, alongside documents from security and intelligence events, and ceremonial medals and certificates from the foreign spy service in Russia – where the deposed Syrian leader Assad has fled.”This award is to the coordinator of the mukh …